# Which is the stronger bond in diborane, B_2H_6: the terminal B-H bond, or the bridging mu_2-BH bonds?

You have a $\text{3-centre-2 electron bond}$.........
You have a $\text{3-centre-2 electron}$ bond bridging the borane nuclei.........versus a $\text{2-centre-2 electron bond}$ in the terminal $B - H$ bonds. A priori, would we not expect the latter to be stronger? In ${H}_{2} B {\left({\mu}_{2} - H\right)}_{2} B {H}_{2}$ the terminal hydride bonds are also shorter than the bridging bonds. Anyway, you are going have to find a text that reports the respective bond-strengths...as a physical scientist you are obliged to quote them.